1. Field of the Invention
This invention relates to a printer, and particularly to a tiny air-pressure balance device between an ink cartridge and an ink bottle in a printer.
2. Description of the Prior Art
In a conventional supply system of a conventional printer, the upper part of every color ink cartridge is connected with a connector, and every connector is connected with a ink tube, of which the other end extends to one side of the printer; the tail end of the ink tube is connected with a connector on the lid of an outside ink bottle (container). The ink in the ink bottle flows into the ink cartridge via the ink tube to form into a supply system so as to enable a printer to print words or drawings.
In the continuous supply system of a conventional printer, the ink bottle mounted outside the printer is a single lid type; the upper part of the bottle lid is furnished with a threaded connector, of which the outer end is connected with an ink tube, while the inner end thereof is connected with a tube extended into the bottle of the ink bottle; the bottle lid must be turned loose or drill a hole in the bottle lid before the ink in the bottle able to flow into the ink cartridge of a printer.
The lid of an outside ink bottle is usually drilled a hole, or is turned loose; however, since the ink is a soluble liquid; the density of the ink would be increased as a result of varying ambient temperature and humidity, and the loss of water in the ink; in that case, the printing quality of the nozzle in the printer would be affected; usually; the nozzle would fail to spray ink, or become useless.
In the conventional separate-type ink cartridge, the outlet of the ink cartridge is furnished with a check valve, which includes a rubber plug, a valve and a spring. By means of the resilience of the spring, the valve and the rubber plug can be maintained in a close contact condition; therefore, the ink in the ink cartridge would not leak out. After the ink cartridge is mounted to the printer, a push rod on the ink cartridge base would push the valve to an open condition; then, the ink would flow, through the gap between the valve and the rubber plug, into the ink passage.